The Collaborative International Dictionary of English v.0.48:
Dashingly \Dash"ing*ly\, adv. Conspicuously; showily. [Colloq.] [1913 Webster] A dashingly dressed gentleman. --Hawthorne. [1913 Webster]WordNet (r) 3.0 (2006):
dashingly adv 1: in a highly fashionable manner; "he was dashingly handsome"